1. Field of the Invention
The present invention relates to an apparatus for integrally connecting a plurality of semiconductor-device characteristic measurement apparatuses having different connection schemes. In particular, the present invention relates to an apparatus that is connected to an electrical-characteristic measurement apparatus and switches the measurement apparatus for an integrated circuit device or a discrete electronic circuit device. For example, the present invention relates to an apparatus that appropriately switches between the capacitance measurement for layer-thickness evaluation and the measurement of gate leakage current for a MOS (metal oxide semiconductor) gate oxide layer, between the evaluation of inter-wire capacitance and the evaluation of inter-wire leakage, and between the evaluation of unction capacitance and that of IV (current-voltage) characteristics for bipolar transistors.
2. Description of the Related Art
Conventionally, a related technology shown in FIG. 1 is known as an apparatus for measuring electrical characteristics of devices to be tested (or hereinafter referred to as “devices under test” (DUT)), such as discrete electronic circuit devices and integrated circuit devices including semiconductors and so on.
FIG. 1 shows a known example of an apparatus for measuring an electrical characteristic or a voltage-current characteristic by using a probe device 100 to probe a DUT 10. Conventionally, one or more units into which a direct-current voltage source, a current source, a voltmeter, and an ammeter are integrated so as to be used in an arbitrary combination are connected to the DUT 10. Each unit is called a source monitor unit or a source measure unit (hereinafter referred to as an “SMU”), and a plurality of SMUs can be used in combination as, for example, an SMU 20. In the known example, a unit (i.e., a capacitance measure unit, and hereinafter referred to as a “CMU”) 22 that can measure electrical capacitance is also used. For measurement using the SMU 20 and the CMU 22, such units are provided in an equipment rack 200 and manually connected to the probe apparatus 100, which probes specific electrical contacts and so on of the DUT 10, via a measurement cable (not shown). When a different characteristic of the DUT 10 is to be measured, an operator manually changes the wires between measuring apparatus for measuring the characteristic and the probe apparatus 100. In such a case, there is an advantage in that an appropriate wiring configuration can be used for each type of measurement. However, there is also a problem in that the measurement operation is inefficient, since the user needs to manually replace connections. Further, when the impedance of connection cables needs to be corrected to measure a capacitance, the measurement cannot be performed with high accuracy in some cases, since the impedance of the connection cables may depend on low the cables are bent. In addition, the SMU 20 and the CMU 22, which are measuring apparatus, should be connected in specific connection ways to the probe apparatus in order to realize accurate measurements. However, since the ways connections are made are generally complicated, the user needs to master them and a user who has not fully mastered them often mixes up connections.